Motor training for young children with cerebral palsy: A single-blind randomized controlled trial.

AIM: To compare the effect of iMOVE (Intensive Mobility training with Variability and Error) therapy with dose-matched conventional therapy on gross motor development and secondary outcomes in young children with cerebral palsy. METHOD: This single-blind, randomized controlled trial included repeated assessments of gross motor function (using the Gross Motor Function Measure) and secondary outcomes during a 12- to 24-week intervention phase and at three follow-up points after treatment. Treatment was delivered three times per week in both groups. Forty-two children aged 12 to 36 months were stratified by age and motor function to ensure equivalence between groups at baseline. RESULTS: Thirty-six children completed treatment and follow-up phases. Treatment fidelity was high and adherence was equivalent between groups (77.3% conventional therapy, 76.2% iMOVE). There were no group differences on the primary (gross motor function after 12 weeks p = 0.18; after 24 weeks p = 0.94) or any secondary (postural control p = 0.88, caregiver satisfaction p = 0.52, child engagement p = 0.98) measure after treatment or at the follow-up points. However, one-third of total participants exceeded predicted change after 12 weeks and 77% exceeded predicted change after 24 weeks of treatment. INTERPRETATION: Our observations indicate a potential dose-response effect of rehabilitation therapy. We further demonstrated that individual therapeutic ingredients can be manipulated. When delivered consistently, both iMOVE and conventional therapy interventions might both be more effective than standard care. WHAT THIS PAPER ADDS: Those receiving iMOVE therapy demonstrated more independent practice time, error, and child-initiation than those receiving the dose-matched control. iMOVE therapy was not superior to the control (conventional physical) therapy. Most participants exceeded predicted change after 24 weeks of treatment.

Impaired Neuromotor Control During Gait in Concussed Adolescents-A Frequency Analysis.

Disruptions in gait function are common after concussion in adolescents; however, the neuromotor control deficits driving these gait disruptions are not well known. Fifteen concussed (age mean [SD]): 17.4 [0.6], 13 females, days since injury: 26.3 [9.9]) and 17 uninjured (age: 18.0 [0.7], 10 females) adolescents completed 3 trials each of single-task gait and dual-task gait (DT). During DT, participants simultaneously walked while completing a serial subtraction task. Gait metrics and variability in instantaneous mean frequency in lower extremity muscles were captured by inertial sensors and surface electromyography, respectively. A 2-way analysis of covariance was used to compare gait metrics across groups and conditions. Functional principal components analysis was used to identify regions of variability in instantaneous mean frequency curves. Functional principal component scores were compared across groups using a Welch statistic. Both groups displayed worse performance on gait metrics during DT condition compared to single-task, with no differences between groups (P < .001). Concussed adolescents displayed significantly greater instantaneous mean frequency, indicated by functional principal component 1, in the tibialis anterior, biceps femoris, and semitendinosus (P < .05) during single-task and DT compared with uninjured adolescents. Our observations suggest that concussed adolescents display inefficient motor unit recruitment lasting longer than 2 weeks following injury, regardless of the addition of a secondary task.

Agreement Between the Gross Motor Ability Estimator-2 and the Gross Motor Ability Estimator-3 in Young Children With Cerebral Palsy.

PURPOSE: The purpose of this study was to determine the agreement between Gross Motor Ability Estimator-2 (GMAE-2) and Gross Motor Ability Estimator-3 (GMAE-3) calculations of Gross Motor Function Measure-66 (GMFM-66) scores in infants and young children with cerebral palsy. METHODS: Data from 53 children 5 to 53 months of age were analyzed. Agreement between GMFM-66 scores using the GMAE-2 and the GMAE-3 was calculated using Bland-Altman plots and interclass correlation coefficients (ICCs). Eleven participants who had at least 1 GMFM-66 score of less than 25 using either method were identified for further analysis. RESULTS: The average difference between GMFM-66 scores was 0.27 for all participants and 0.63 for the subset of lower-scoring participants. Good agreement was found for GMFM-66 scores for all participants (ICC = 0.998) and for subset of lower-scoring participants (ICC = 0.879). CONCLUSIONS: High levels of agreement exist between the GMAE-2 and the GMAE-3, which suggests that scores are comparable using either algorithm.

Unweighting infants reveals hidden motor skills.

We investigated the role of rate limiting factors in development using walking as a model system. The achievement of bipedal posture and locomotion are among the most significant achievements in an infant's first year, with poor balance and weak muscles long proposed as the rate limiting factors. Compensating for either may reveal upright motor skill that has not yet emerged in the infant's natural repertoire. To probe this question, we unweighted prewalking infants and measured their performance in various standing and walking behaviors while unweighted compared to baseline. Our secondary objective was to determine if the influence of unweighting was related to infants' locomotor experience. Infants stood unsupported for longer durations with 20% or 40% unweighting. Infants took more independent steps and more steps with one hand held with 40% unweighting. No differences in transition to/from standing were observed. Locomotor experience was related to the influence of unweighting during cruising and walking with a push toy. This is the first report of more advanced motor skills-longer periods of unsupported standing and the emergence of independent walking-revealed by unweighting infants. We interpret our observations to suggest that the refinement of motor control needed to support bipedal posture and locomotion precedes the functional emergence of these skills in infants. In other words, the musculoskeletal components required for walking are slower to develop than the neurological factors - and consequently may be the rate limiters. We further suggest that training regimens including unweighting should be explored in infants with motor delays.

The relationship between family empowerment and fine motor, gross motor and cognitive skills in young children with cerebral palsy.

BACKGROUND: Family empowerment in families of young children with cerebral palsy (CP) is an important consideration because the first few years of life can be overwhelming for parents. The purpose of this research was to investigate the relationship between family empowerment, fine motor (FM), gross motor (GM) and cognitive development in children with CP who were under 3 years of age. METHODS: Forty-one children with a mean age of 23.8 months participated in this study. The Family Empowerment Scale (FES) was completed by the participants' parents, whereas the FM, GM and cognitive subscales of the Bayley Scales of Infant and Toddler Development Third edition (B-III) were administered by physical therapists. RESULTS: Statistically significant positive correlations were found between the FES total and B-III raw scores for FM, GM and cognitive subscales with coefficients ranging from 0.35 to 0.41. Significant relationships were also found between the FES Community subscale and the B-III FM, GM and cognitive subscales. CONCLUSIONS: This study provides evidence of a relationship between family empowerment and FM, GM and cognitive abilities in young children with CP, with a greater severity of impairments related to lower levels of caregiver empowerment.

Infants at risk for physical disability may be identified by measures of postural control in supine.

BACKGROUND: Early detection of delay or impairment in motor function is important to guide clinical management and inform prognosis during a critical window for the development of motor control in children. The purpose of this study was to investigate the ability of biomechanical measures of early postural control to distinguish infants with future impairment in motor control from their typically developing peers. METHODS: We recorded postural control from infants lying in supine in several conditions. We compared various center of pressure metrics between infants grouped by birth status (preterm and full term) and by future motor outcome (impaired motor control and typical motor control). RESULTS: One of the seven postural control metrics-path length-was consistently different between groups for both group classifications and for the majority of conditions. CONCLUSIONS: Quantitative measures of early spontaneous infant movement may have promise to distinguish early in life between infants who are at risk for motor impairment or physical disability and those who will demonstrate typical motor control. Our observation that center of pressure path length may be a potential early marker of postural instability and motor control impairment needs further confirmation and further investigation to elucidate the responsible neuromotor mechanisms. IMPACT: The key message of this article is that quantitative measures of infant postural control in supine may have promise to distinguish between infants who will demonstrate future motor impairment and those who will demonstrate typical motor control. One of seven postural control metrics-path length-was consistently different between groups. This metric may be an early marker of postural instability in infants at risk for physical disability.

The relationship between the Family Empowerment Scale and Gross Motor Function Measure-66 in Young Children with cerebral palsy.

BACKGROUND: Cerebral palsy (CP) is the most common cause of motor disability in children. A concept to consider in order to meet the needs of children with CP and their families is family empowerment. Family empowerment can be defined as the process by which families acquire the skills, knowledge and resources to allow them to gain control and improve the quality of their lives. The relationship between gross motor function and family empowerment may be important because children with CP vary so widely in their ability to perform motor skills, which may affect their family's levels of empowerment. The purpose of this research was to investigate the relationship between the Family Empowerment Scale (FES) and Gross Motor Function Measure-66 (GMFM-66) in children with CP who were under 3 years of age. METHODS: Forty-one children with a mean age of 23.8 months participated in this study. The FES was completed by the participants' parents or regular caregivers and includes a total score and subscales of empowerment in the family, in service situations and in community/political environments. The GMFM-66 was administered by a physical therapist and consists of a total score of gross motor function (GMFM-66) and subscores for Dimension B (sitting), Dimension C (crawling and kneeling), Dimension D (standing) and Dimension E (walking, running and jumping). RESULTS: Statistically significant positive correlations were found between the FES total and GMFM (total score and Dimensions B-E) with coefficients varying from 0.43-0.62. Significant relationships were also found between most subscales of the FES and the GMFM-66. CONCLUSIONS: This study provides evidence of a relationship between family empowerment and gross motor function in young children with CP and suggests that caregivers of children with higher gross motor function report higher levels of self-efficacy.

The Use of Dynamic Weight Support with Principles of Infant Learning in a Child with Cerebral Palsy: A Case Report.

AIMS: Typical infant movement is characterized by a high degree of motor exploration, error, and variability. However, children with cerebral palsy (CP) often cannot create these experiences due to their neuromotor impairments. The purpose of this case study is to describe a 6-month course of physical therapy (PT) incorporating principles of infant motor learning using dynamic weight support (DWS) in a child with CP. METHODS: The child was a 27-month-old girl with diplegic CP who functioned at Gross Motor Function Classification System Level IV. The child received 68 PT sessions over a six-month period. DWS was used during therapy to encourage motor practice. The therapy area was arranged to encourage active exploration, motor variability, and error experience. Gross motor function, postural control, parent perception of performance, and parent satisfaction were measured before, during, and after the course of therapy. RESULTS: Gross motor function increased during the treatment beyond the level predicted from natural progression. Postural control fluctuated and demonstrated no appreciable improvement. Parent-perceived performance and satisfaction improved on three of four goals. CONCLUSIONS: Using DWS to incorporate principles of infant learning may have facilitated the development of gross motor skills in a child with diplegic CP.

Linear and Nonlinear Measures of Postural Control in a Toddler With Cerebral Palsy: Brief Report.

PURPOSE: The purpose of this study was to describe changes in linear and nonlinear measures of postural control along with motor outcomes in a young child with cerebral palsy. SUMMARY OF KEY POINTS: Posturography in sitting and standing, the Gross Motor Function Measure-66 (GMFM-66), and the Early Clinical Assessment of Balance (ECAB) were performed prior to, during, and after physical therapy. The child demonstrated independent sitting throughout the study and developed independent standing during the study. He made improvements in the GMFM-66 and ECAB throughout the study. Higher average values were found in all linear and nonlinear measures in standing when compared to sitting, which may indicate less predictable movement due to less experience with standing. RECOMMENDATIONS FOR CLINICAL PRACTICE: Greater variability and lower predictability in postural control likely reflect early stages of skill acquisition. Research is needed to understand the optimal levels of movement variability and predictability.

iMOVE: Intensive Mobility training with Variability and Error compared to conventional rehabilitation for young children with cerebral palsy: the protocol for a single blind randomized controlled trial.

BACKGROUND: Cerebral palsy (CP) is the most common cause of physical disability in children. The best opportunity to maximize lifelong independence is early in motor development when there is the most potential for neuroplastic change, but how best to optimize motor ability during this narrow window remains unknown. We have systematically developed and pilot-tested a novel intervention that incorporates overlapping principles of neurorehabilitation and infant motor learning in a context that promotes upright mobility skill and postural control development. The treatment, called iMOVE therapy, was designed to allow young children with CP to self-initiate motor learning experiences similar to their typically developing peers. This manuscript describes the protocol for a subsequent clinical trial to test the efficacy of iMOVE therapy compared to conventional therapy on gross motor development and other secondary outcomes in young children with CP. METHODS: The study is a single-blind randomized controlled trial. Forty-two participants with CP or suspected CP between the ages of 1-3 years will be randomized to receive either the iMOVE or conventional therapy group. Distinguishing characteristics of each group are detailed. Repeated measures of gross motor function will be collected throughout the 12-24 week intervention phase and at three follow-up points over one year post therapy. Secondary outcomes include measures of postural control, physical activity, participation and caregiver satisfaction. DISCUSSION: This clinical trial will add to a small, but growing, body of literature on early interventions to optimize the development of motor control in young children with CP. The information learned will inform clinical practice of early treatment strategies and may contribute to improving the trajectory of motor development and reducing lifelong physical disability in individuals with CP. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02340026 . Registered January 16, 2015.

Stochastic resonance stimulation improves balance in children with cerebral palsy: a case control study.

BACKGROUND: Stochastic Resonance (SR) Stimulation has been used to enhance balance in populations with sensory deficits by improving the detection and transmission of afferent information. Despite the potential promise of SR in improving postural control, its use in individuals with cerebral palsy (CP) is novel. The objective of this study was to investigate the immediate effects of electrical SR stimulation when applied in the ankle muscles and ligaments on postural stability in children with CP and their typically developing (TD) peers. METHODS: Ten children with spastic diplegia (GMFCS level I- III) and ten age-matched TD children participated in this study. For each participant the SR sensory threshold was determined. Then, five different SR intensity levels (no stimulation, 25, 50, 75, and 90% of sensory threshold) were used to identify the optimal SR intensity for each subject. The optimal SR and no stimulation condition were tested while children stood on top of 2 force plates with their eyes open and closed. To assess balance, the center of pressure velocity (COPV) in anteroposterior (A/P) and medial-lateral (M/L) direction, 95% COP confidence ellipse area (COPA), and A/P and M/L root mean square (RMS) measures were computed and compared. RESULTS: For the CP group, SR significantly decreased COPV in A/P direction, and COPA measures compared to the no stimulation condition for the eyes open condition. In the eyes closed condition, SR significantly decreased COPV only in M/L direction. Children with CP demonstrated greater reduction in all the COP measures but the RMS in M/L direction during the eyes open condition compared to their TD peers. The only significant difference between groups in the eyes closed condition was in the COPV in M/L direction. CONCLUSIONS: SR electrical stimulation may be an effective stimulation approach for decreasing postural sway and has the potential to be used as a therapeutic tool to improve balance. Applying subject-specific SR stimulation intensities is recommended to maximize balance improvements. Overall, balance rehabilitation interventions in CP might be more effective if sensory facilitation methods, like SR, are utilized by the clinicians. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02456376; 28 May 2015 (Retrospectively registered); https://clinicaltrials.gov/ct2/show/NCT02456376 .

A new methodological approach to characterize selective motor control in children with cerebral palsy.

Introduction: Despite being a primary impairment in individuals with cerebral palsy (CP), selective motor control (SMC) is not routinely measured. Personalized treatment approaches in CP will be unattainable without the ability to precisely characterize the types and degrees of impairments in motor control. The objective of this study is to report the development and feasibility of a new methodological approach measuring muscle activation patterns during single-joint tasks to characterize obligatory muscle co-activation patterns that may underly impaired SMC. Methods: Muscle activation patterns were recorded during sub-maximal voluntary isometric contraction (sub-MVIC) tasks at the hip, knee, and ankle with an interactive feedback game to standardize effort across participants. We calculated indices of co-activation, synergistic movement, mirror movement, and overflow (indices range 0-2, greater scores equal to greater impairment in SMC) for each isolated joint task in 15 children - 8 with typical development (TD) (mean age 4.7 ± 1.0 SD years) and 7 with CP (mean age 5.8 ± 0.7 SD years). Indices were compared with Mann-Whitney tests. The relationships between the indices and gross motor function (GMFM-66) were examined with Pearson's r. Results: Mean indices were higher in the CP vs. the TD group for each of the six tasks, with mean differences ranging from 0.05 (abduction and plantarflexion) to 0.44 (dorsiflexion). There was great inter-subject variability in the CP group such that significant group differences were detected for knee flexion mirroring (p = 0.029), dorsiflexion coactivation (p = 0.021), and dorsiflexion overflow (p = 0.014). Significant negative linear relations to gross motor function were found in all four indices for knee extension (r = -0.56 to -0.75), three of the indices for ankle dorsiflexion (r = -0.68 to -0.78) and in two of the indices for knee flexion (r = -0.66 to -0.67), and ankle plantarflexion (r = -0.53 to -0.60). Discussion: Indices of coactivation, mirror movement, synergy, and overflow during single-joint lower limb tasks may quantify the type and degree of impairment in SMC. Preliminary concurrent validity between several of the indices of SMC and gross motor function was observed. Our findings established the feasibility of a new methodological approach that quantifies muscle activation patterns using electromyography paired with biofeedback during single-joint movement.

Towards an AI-driven soft toy for automatically detecting and classifying infant-toy interactions using optical force sensors.

Introduction: It is crucial to identify neurodevelopmental disorders in infants early on for timely intervention to improve their long-term outcomes. Combining natural play with quantitative measurements of developmental milestones can be an effective way to swiftly and efficiently detect infants who are at risk of neurodevelopmental delays. Clinical studies have established differences in toy interaction behaviors between full-term infants and pre-term infants who are at risk for cerebral palsy and other developmental disorders. Methods: The proposed toy aims to improve the quantitative assessment of infant-toy interactions and fully automate the process of detecting those infants at risk of developing motor delays. This paper describes the design and development of a toy that uniquely utilizes a collection of soft lossy force sensors which are developed using optical fibers to gather play interaction data from infants laying supine in a gym. An example interaction database was created by having 15 adults complete a total of 2480 interactions with the toy consisting of 620 touches, 620 punches-"kick substitute," 620 weak grasps and 620 strong grasps. Results: The data is analyzed for patterns of interaction with the toy face using a machine learning model developed to classify the four interactions present in the database. Results indicate that the configuration of 6 soft force sensors on the face created unique activation patterns. Discussion: The machine learning algorithm was able to identify the distinct action types from the data, suggesting the potential usability of the toy. Next steps involve sensorizing the entire toy and testing with infants.

Neurophysiological and gait outcomes during a dual-task gait assessment in concussed adolescents.

BACKGROUND: Gait deficits are common after concussion in adolescents. However, the neurophysiological underpinnings of these gait deficiencies are currently unknown. Thus, the goal of this study was to compare spatiotemporal gait metrics, prefrontal cortical activation, and neural efficiency between concussed adolescents several weeks from injury and uninjured adolescents during a dual-task gait assessment. METHODS: Fifteen concussed (mean age[SD]: 17.4[0.6], 13 female, days since injury: 26.3[9.9]) and 17 uninjured adolescents (18.0[0.7], 10 female) completed a gait assessment with three conditions repeated thrice: single-task walking, single-task subtraction, and dual-task, which involved walking while completing a subtraction task simultaneously. Gait metrics were measured using an inertial sensor system. Prefrontal cortical activation was captured via functional near-infrared spectroscopy. Neural efficiency was calculated by relating gait metrics to prefrontal cortical activity. Differences between groups and conditions were examined, with corrections for multiple comparisons. FINDINGS: There were no significant differences in gait metrics between groups. Compared to uninjured adolescents, concussed adolescents displayed significantly greater prefrontal cortical activation during the single-task subtraction (P = 0.01) and dual-task (P = 0.01) conditions with lower neural efficiency based on cadence (P = 0.02), gait cycle duration (P = 0.03), step duration (P = 0.03), and gait speed (P = 0.04) during the dual-task condition. INTERPRETATION: Our findings suggest that several weeks after injury concussed adolescents demonstrate lower neural efficiency and display a cost to gait performance when cognitive demand is high, e.g., while multitasking, suggesting that the concussed adolescent brain is less able to compensate when attention is divided between two concurrent tasks.

Locomotor learning in infants at high risk for cerebral palsy: A study protocol.

Background: Physical disability in individuals with cerebral palsy (CP) creates lifelong mobility challenges and healthcare costs. Despite this, very little is known about how infants at high risk for CP learn to move and acquire early locomotor skills, which set the foundation for lifelong mobility. The objective of this project is to characterize the evolution of locomotor learning over the first 18 months of life in infants at high risk for CP. To characterize how locomotor skill is learned, we will use robotic and sensor technology to provide intervention and longitudinally study infant movement across three stages of the development of human motor control: early spontaneous movement, prone locomotion (crawling), and upright locomotion (walking). Study design: This longitudinal observational/intervention cohort study (ClinicalTrials.gov Identifier: NCT04561232) will enroll sixty participants who are at risk for CP due to a brain injury by one month post-term age. Study participation will be completed by 18 months of age. Early spontaneous leg movements will be measured monthly from 1 to 4 months of age using inertial sensors worn on the ankles for two full days each month. Infants who remain at high risk for CP at 4 months of age, as determined from clinical assessments of motor function and movement quality, will continue through two locomotor training phases. Prone locomotor training will be delivered from 5 to 9 months of age using a robotic crawl training device that responds to infant behavior in real-time. Upright locomotor training will be delivered from 9 to 18 months of age using a dynamic weight support system to allow participants to practice skills beyond their current level of function. Repeated assessments of locomotor skill, training characteristics (such as movement error, variability, movement time and postural control), and variables that may mediate locomotor learning will be collected every two months during prone training and every three months during upright training. Discussion: This study will develop predictive models of locomotor skill acquisition over time. We hypothesize that experiencing and correcting movement errors is critical to skill acquisition in infants at risk for CP and that locomotor learning is mediated by neurobehavioral factors outside of training.Project Number 1R01HD098364-01A1.ClinicalTrials.gov Identifier: NCT04561232.

Quantifying interaction with robotic toys in pre-term and full-term infants.

Infants born pre-term are at an increased risk for developmental, behavioral, and motor delay and subsequent disability. When these problems are detected early, clinical intervention can be effective at improving functional outcomes. Current methods of early clinical assessment are resource intensive, require extensive training, and do not always capture infants' behavior in natural play environments. We developed the Play and Neuro Development Assessment (PANDA) Gym, an affordable, mechatronic, sensor-based play environment that can be used outside clinical settings to capture infant visual and motor behavior. Using a set of classification codes developed from the literature, we analyzed videos from 24 pre-term and full-term infants as they played with each of three robotic toys designed to elicit different types of interactions-a lion, an orangutan, and an elephant. We manually coded for frequency and duration of toy interactions such as kicking, grasping, touching, and gazing. Pre-term infants gazed at the toys with similar frequency as full-term infants, but infants born full-term physically engaged more frequently and for longer durations with the robotic toys than infants born pre-term. While we showed we could detect differences between full-term and pre-term infants, further work is needed to determine whether differences seen were primarily due to age, developmental delays, or a combination.

Acceptability and potential effectiveness of a foot drop stimulator in children and adolescents with cerebral palsy.

AIM: Ankle-foot orthoses are the standard of care for foot drop in cerebral palsy (CP), but may overly constrain ankle movement and limit function in those with mild CP. Functional electrical stimulation (FES) may be a less restrictive and more effective alternative, but has rarely been used in CP. The primary objective of this study was to conduct the first trial in CP examining the acceptability and clinical effectiveness of a novel, commercially available device that delivers FES to stimulate ankle dorsiflexion. METHOD: Twenty-one individuals were enrolled (Gross Motor Function Classification System [GMFCS] levels I and II, mean age 13y 2mo). Gait analyses in FES and non-FES conditions were performed at two walking speeds over a 4 month period of device use. Measures included ankle kinematics and spatiotemporal variables. Differences between conditions were revealed using repeated measures multivariate analyses of variance. RESULTS: Nineteen individuals (nine females, 10 males; mean age 12y 11mo, range 7y 5mo to 19y 11mo; 11 at GMFCS level I, eight at level II) completed the FES intervention, with all but one choosing to continue using FES beyond that phase. Average daily use was 5.6 hours (SD 2.3). Improved dorsiflexion was observed during swing (mean and peak) and at foot-floor contact, with partial preservation of ankle plantarflexion at toe-off when using the FES at self-selected and fast walking speeds. Gait speed was unchanged. INTERPRETATION: This FES device was well accepted and effective for foot drop in those with mild gait impairments from CP.

The relationship between spasticity and muscle volume of the knee extensors in children with cerebral palsy.

PURPOSE: The purpose of this study was to examine the relationship between spasticity and muscle volume in children with cerebral palsy (CP), using isokinetic dynamometry and magnetic resonance imaging. METHODS: A retrospective sample of 8 children with diplegic CP was analyzed. One set of 10 passive knee flexion movements was completed at a velocity of 180° per second with concurrent surface electromyography of the medial hamstrings (MH) and vastus lateralis (VL) to assess knee extensor spasticity. Magnetic resonance imaging was used to measure maximum cross-sectional area and muscle volume of the quadriceps femoris. RESULTS: The quadriceps femoris muscle volume was positively correlated with MH reflex activity, VL reflex activity, MH/VL co-contraction, and peak knee extensor passive torque (P < .05). CONCLUSION: The present findings suggest that higher levels of knee extensor muscle spasticity are associated with greater quadriceps muscle volume in children with spastic diplegic CP.

A MEG compatible, interactive IR game paradigm for the study of visuomotor reach-to-target movements in young children and clinical populations: The Target-Touch Motor Task.

BACKGROUND: The conventional focus on discrete finger movements (i.e., index finger flexion or button-box key presses) has been an effective method to study neuromotor control using magnetoencephalography (MEG). However, this approach is challenging for young children and not possible for some people with physical disability. NEW METHOD: We have developed a novel, interactive MEG compatible reach-to-target task to investigate neuromotor function, specifically for use with young children. We used an infrared touch-screen frame to detect responses to targets presented using custom software. The game can be played using a conventional computer monitor or during MEG recordings via projector. We termed this game the Target-Touch Motor Task (TTMT). RESULTS: We demonstrate that the TTMT is a feasible motor task for use with young children including children with physical impairments. TTMT response-to-target trial counts are also comparable to conventional methods. Artifacts from the touch screen, while present > 100 Hz, did not affect MEG source analysis in the beta band (14-30 Hz). MEG responses during TTMT game play reveal robust cortical activity from expected areas of motor cortex as typically observed following movements of the upper limb. COMPARISON WITH EXISTING METHOD(S): The TTMT paradigm allows participation by individuals with a broad range of motor abilities on a reach-to-target' functional task rather than conventional tasks focusing on discrete finger movements. CONCLUSIONS: The TTMT is well suited for young children and successfully activates expected motor cortical areas. The TTMT opens-up new opportunities for the assessment of motor function across the lifespan, including for children with physical limitations.

Walking speed influences spatiotemporal but not symmetry measures of gait in children and adolescents with hemiplegia.

BACKGROUND: The measurement of gait is likely influenced by walking speed in children with hemiplegia, but this relationship is not well characterized. RESEARCH QUESTION: What is the influence of walking speed on spatiotemporal and symmetry measures of gait in children with hemiplegia, with consideration of side and footwear condition? METHODS: Children with hemiparetic gait due to stroke were recruited for a small pilot intervention study. Participants walked at self-selected and fast speeds while barefoot and while wearing shoes. Data from baseline sessions were included in this analysis. The influence of walking speed on five spatiotemporal gait measures was determined using a generalized estimating equation to calculate the proportion of variability in the gait measures that was explained by walking speed. Differences between sides and footwear conditions, and the relationships between walking speed and two symmetry measures, are also reported. RESULTS: A total of 820 steps were analyzed from ten children (11.2 ± 4.1 years). Walking velocity significantly influenced all spatiotemporal measures of gait. As speed increased, step length increased and all temporal measures decreased, on both paretic and nonparetic sides. Wearing shoes increased step length and stance time for both paretic and nonparetic sides, and slowed step time on the nonparetic side. Regardless of footwear, the paretic side demonstrated slower step and swing times, and faster stance and single support times. We did not observe significant relationships between walking speed and gait symmetry. SIGNIFICANCE: Our observations suggest that walking speed alone influences the spatiotemporal measurement of gait in children with hemiplegia and should be considered in the interpretation of walking function. Yet, controlling for walking speed is often not feasible or not preferred in this population. We offer suggestions for clinicians and researchers who seek to measure gait during overground walking at freely-selected speeds.